The present invention relates to a vacuum cleaner having a dual filter structure whereby the collected dust and dirt is dually filtered out, thereby protecting the motor against choking due to dust. More particularly, the present invention relates to a vacuum cleaner having a dual filter structure of which one filter unit is subjected to timely vibration, thereby protecting the same against choking due to dust entrained thereon.
The vacuum cleaner is known, and widely used for house, factory and office cleaning. The vacuum cleaner is provided with a filter whereby the collected dust and dirt is filtered out. The conventional filter is provided in the form of a bag, commonly called a filter bag. However, it is difficult to filter out the dust and dirt with such a filter bag, and unfiltered impurities pass through the filter meshes, and enter into the cage of the motor, where they stick to every oily surface of the motor components. Eventually, the build-up of the impurities causes choking of the motor, and at least reduces its efficiency. Choking often leads to seizure, and shortens the life of the motor. In addition, the filter elements are also liable to become blocked.